The purpose of this project is to test the in vivo viability of red cells stored for 28 days in CLX plastic. Ten to twelve individuals will be tested with this method and results will be compared to in vivo viability of red cells stored for 42 days in standard diethylhexylphthalate. It is hoped that satisfactory in vivo viability and in vitro parameters will be maintained without the use of the DEHP plasticizer which is a potential toxin. The CLX plastic is a licensed medium for storage of platelets.